The subject matter disclosed herein relates to joined components, and more particularly to an assembly for joining plastic components, as well as a method of joining such plastic components.
Various methods and assemblies for permanently joining plastic components are currently employed. “Hot-plate” welding requires a lengthy process based, in part, on getting the system up to operating temperature. Welding produces plastic strings or hair due to direct contact with molten plastic. Additionally, generation of fumes and smoke must be exhausted from the working environment. A large percentage of the energy required escapes the system as waste heat that often undesirably affects areas other than the welding area of the plastic components. Residue build up on the heating surface requires frequent cleaning and overall process control is often heavily limited.
Infrared welding often requires shielding to protect the plastic components from heat, however, this is problematic based on thermal expansion that causes the shield to warp and distort. As is the case with “hot-plate” welding, a large percentage of the energy required escapes the system as waste heat. Additionally, complex electric wiring is required when using multiple infrared bulbs and infrared emitters are difficult to arrange in a pattern that supports the product configuration.
Infrared laser welding typically requires an opaque component and a transparent component, clamped together in a desired configuration. Laser energy, guided robotically, passes through the transparent component at the weld location to heat the opaque material to a melt temperature, with the heat then being conducted to the transparent material to achieve melt temperature, thereby welding the plastic components together at the corresponding melting locations. Undesirably, laser power in such a process often overheats the plastic before heat is conducted throughout the material. Additionally, attempts to use this method where both components are opaque require the components to be separated during the laser exposure to allow access to the ribs. This results in the need to traverse the pattern in its entirety before joining the components together. The plastic at the beginning of the pattern will have a different heat profile than the plastic at the end of the pattern resulting from cooling at the beginning of the pattern as the pattern is being traversed.